Hemp composites

ABSTRACT

A hemp composite includes hemp, paper, and oil. Making a hemp composite includes processing hemp to yield a processed hemp. The processed hemp includes water. Making a hemp composite further includes combining the processed hemp with paper and oil to yield a hemp mixture, removing at least some of the water from the hemp mixture, and drying the hemp mixture to yield the hemp composite.

CROSS-REFERENCE TO RELATED APPLICATION

This application claims the benefit of U.S. Patent Application 63/239,212 filed on Aug. 31, 2021, which is incorporated herein by reference in its entirety.

TECHNICAL FIELD

This invention relates to methods of making hemp composites and articles (e.g., hemp-containing paper products) made from the hemp composites.

BACKGROUND

Paper products have a variety of uses. In one example, corrugated boxes are used to package goods for transportation. Paper products, including corrugated boxes, are usually made with a feedstock including wood from trees (e.g., softwood trees, hardwood trees, or a combination thereof). Trees suitable for the production of paper products typically take about 20 years to reach sufficient size for harvesting.

SUMMARY

Inventive aspects of this disclosure include methods of making hemp composites and articles made from hemp composites. In some embodiments, making hemp-containing products includes processing hemp (e.g., hemp stalks), and combining the processed hemp with paper and oil to yield a hemp mixture, removing water from the hemp mixture, and drying the hemp mixture to yield a hemp composite. The paper can be post-consumer recycled paper. A weight ratio of hemp to water in the hemp mixture can be adjusted to achieve a selected elasticity of the hemp composite. In some examples, the hemp composite is in the form of cardboard (e.g., corrugated cardboard), masonry bricks, concrete masonry units, drywall and gypsum boards, and containers, including food grade and non-food grade containers.

In a first general aspect, making a hemp composite includes processing hemp to yield a processed hemp. The processed hemp includes water. The first general aspect further includes combining the processed hemp with paper and oil to yield a hemp mixture, removing at least some of the water from the hemp mixture, and drying the hemp mixture to yield the hemp composite.

Implementation of the first general aspect can include one or more of the following features.

In some cases, the hemp includes hemp stalks. In some implementations, processing the hemp includes shredding and pulverizing the hemp. In certain implementations, processing the hemp further includes combining the hemp with boiling water to yield a pulp mixture. In some cases, processing the hemp further includes breaking down cell walls of the hemp in the pulp mixture. In some implementations, breaking down the cell walls of the hemp includes combining the pulp mixture with sodium bicarbonate. Certain implementations further include adjusting a weight ratio of hemp to water in the pulp mixture to achieve a selected elasticity of the hemp composite. Some implementations further include removing at least some of the water from the pulp mixture to yield a drained pulp mixture. Some cases further include combining the drained pulp mixture with water at ambient temperature to yield the processed hemp. The paper can be shredded. In some implementations, the paper includes post-consumer recycled paper. In some cases, the oil includes bio-oil. In certain implementations, the bio-oil includes amines. Certain implementations further include shaping the hemp mixture before drying the hemp mixture. In some cases, the hemp composite is oil-infused. An article can be formed from the hemp mixture of the first general aspect. In some cases, the article is one of cardboard, clay pigeons, masonry bricks, concrete masonry units, gypsum boards, food-grade containers, and non-food grade containers. In some implementations, the cardboard includes a corrugated cardboard box.

In a second general aspect, a hemp composite includes hemp, paper, and oil.

Implementation of the second general aspect can include one or more of the following features.

In some cases, the hemp includes hemp stalks. In some implementations, the paper includes post-consumer recycled paper. In some implementations, the oil includes bio-oil. An article can include the composite of the second general aspect. In some cases, the article is one of cardboard, clay pigeons, masonry bricks, concrete masonry units, gypsum boards, food-grade containers, and non-food grade containers. In certain implementations, the cardboard includes a corrugated cardboard box.

The processes and composites described in this disclosure provide various advantages. For example, hemp takes only four months to become harvestable, and thus can be harvested about 60 times more than wood trees in the same time span. The combination of hemp and post-consumer recycled paper provides a low-cost, biodegradable, and biologically safe option to address a growing demand for packaging and other products. The hemp composite also decreases the use of trees, thereby increasing the amount of carbon dioxide sequestered from the atmosphere. The hemp composite has carbon-negative characteristics and can absorb select gaseous emissions from the air.

The details of one or more embodiments of the subject matter of this disclosure are set forth in the accompanying drawings and the description. Other features, aspects, and advantages of the subject matter will become apparent from the description, the drawings, and the claims.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a flow chart showing steps in the process of making a hemp composite.

DETAILED DESCRIPTION

FIG. 1 shows steps in a process for making a hemp composite. In 102, hemp is processed. The hemp can include hemp stalks, hemp shivs, or both. Processing the hemp includes reducing a size of the hemp, combining the hemp with water, and breaking down the cellular structure of the hemp. In 104, the processed hemp is combined with paper and oil to yield a hemp mixture. The paper is typically post-consumer recycled paper. The paper can be shredded. The oil can be an amine-rich bio-oil. In 106, water is removed from the hemp mixture. A weight ratio of hemp to water in the hemp mixture can be adjusted to achieve a selected elasticity of the hemp composite. In 108, the hemp mixture is dried to yield an oil-infused hemp composite. The paper and oil increases the durability, adhesion, and elasticity of the hemp composite.

Before drying, the hemp composite can be shaped (e.g., molded) into various articles, such as biodegradable containers and bricks (e.g., terracotta and concrete masonry units) for various types of construction, and clay pigeons. The hemp composite can also be added to drywall, gypsum boards, food-grade containers, and non-food grade containers. The strength of hemp at the cellular level, which exceeds that of wood, contributes to the strength and durability of these products.

In one embodiment of process 100, hemp is used to make corrugated cardboard (e.g., for use in boxes). In this embodiment, hemp stalks are shredded and pulverized. The shredded, pulverized hemp stalks are combined with boiling water and boiled until a pulp mixture is formed (e.g., about one hour). The pulp mixture is treated to break down cell walls of the hemp. In one example, treating the pulp mixture includes combining sodium bicarbonate with the boiling pulp mixture. Water is drained from the pulp mixture, and the pulp is combined with water at ambient temperature to yield a washed pulp mixture. Post-consumer recycled paper and amine-rich bio-oils are combined with the washed pulp mixture to yield a hemp mixture. A silk strainer is used to remove water from the hemp mixture and form hemp sheets. The hemp sheets are dried to yield a hemp composite, for example, by laying the sheets on an absorbent material and cold pressing the absorbent material to remove water and promote uniform drying. The hemp composite is rolled and can be stored for later processing in corrugating machinery to yield hemp-containing corrugated cardboard. The hemp-containing corrugated cardboard can provide the same strength as a thicker product made from wood, and provides an environmentally friendly alternative to conventional corrugated cardboard.

Although this disclosure contains many specific embodiment details, these should not be construed as limitations on the scope of the subject matter or on the scope of what may be claimed, but rather as descriptions of features that may be specific to particular embodiments. Certain features that are described in this disclosure in the context of separate embodiments can also be implemented, in combination, in a single embodiment. Conversely, various features that are described in the context of a single embodiment can also be implemented in multiple embodiments, separately, or in any suitable sub-combination. Moreover, although previously described features may be described as acting in certain combinations and even initially claimed as such, one or more features from a claimed combination can, in some cases, be excised from the combination, and the claimed combination may be directed to a sub-combination or variation of a sub-combination.

Particular embodiments of the subject matter have been described. Other embodiments, alterations, and permutations of the described embodiments are within the scope of the following claims as will be apparent to those skilled in the art. While operations are depicted in the drawings or claims in a particular order, this should not be understood as requiring that such operations be performed in the particular order shown or in sequential order, or that all illustrated operations be performed (some operations may be considered optional), to achieve desirable results.

Accordingly, the previously described example embodiments do not define or constrain this disclosure. Other changes, substitutions, and alterations are also possible without departing from the spirit and scope of this disclosure. 

What is claimed is:
 1. A method of making a hemp composite, the method comprising: processing hemp to yield a processed hemp, wherein the processed hemp comprises water; combining the processed hemp with paper and oil to yield a hemp mixture; removing at least some of the water from the hemp mixture; and drying the hemp mixture to yield the hemp composite.
 2. The method of claim 1, wherein the hemp comprises hemp stalks.
 3. The method of claim 1, wherein processing the hemp comprises shredding and pulverizing the hemp.
 4. The method of claim 3, wherein processing the hemp further comprises combining the hemp with boiling water to yield a pulp mixture.
 5. The method of claim 4, wherein processing the hemp further comprises breaking down cell walls of the hemp in the pulp mixture.
 6. The method of claim 5, wherein breaking down the cell walls of the hemp comprises combining the pulp mixture with sodium bicarbonate.
 7. The method of claim 4, further comprising adjusting a weight ratio of hemp to water in the pulp mixture to achieve a selected elasticity of the hemp composite.
 8. The method of claim 4, further comprising removing at least some of the water from the pulp mixture to yield a drained pulp mixture.
 9. The method of claim 8, further comprising combining the drained pulp mixture with water at ambient temperature to yield the processed hemp.
 10. The method of claim 1, wherein the paper is shredded.
 11. The method of claim 10, wherein the paper comprises post-consumer recycled paper.
 12. The method of claim 1, wherein the oil comprises bio-oil.
 13. The method of claim 12, wherein the bio-oil comprises amines.
 14. The method of claim 1, further comprising shaping the hemp mixture before drying the hemp mixture.
 15. The method of claim 1, wherein the hemp composite is oil-infused.
 16. An article formed from the hemp mixture of claim
 1. 17. The article of claim 16, wherein the article is one of cardboard, clay pigeons, masonry bricks, concrete masonry units, gypsum boards, food-grade containers, and non-food grade containers.
 18. The article of claim 17, wherein the cardboard comprises a corrugated cardboard box.
 19. A hemp composite comprising: hemp; paper; and oil.
 20. The composite of claim 19, wherein the hemp comprises hemp stalks.
 21. The composite of claim 19, wherein the paper comprises post-consumer recycled paper.
 22. The composite of claim 19, wherein the oil comprises bio-oil.
 23. An article comprising the composite of claim
 19. 24. The article of claim 23, wherein the article is one of cardboard, clay pigeons, masonry bricks, concrete masonry units, gypsum boards, food-grade containers, and non-food grade containers.
 25. The article of claim 24, wherein the cardboard comprises a corrugated cardboard box. 